The domain of a function is the set of input values the function can take
The radical function is not given; so, I will provide a general explanation
Assume the radical function is:

The denominator of the above function cannot be negative.
So, we express the denominator as follows

Subtract 12 from both sides

Divide both sides by -2

So, the possible values of x the function can take are less than 6
Hence, the domain of the radical function is ![[-\infty,6]](https://tex.z-dn.net/?f=%5B-%5Cinfty%2C6%5D)
Read more about domain at:
brainly.com/question/4173276